What CBM capacity do you use per container?

Usable (practical) volumes are about 33 CBM for a 20ft, 67 CBM for a 40ft, and 76 CBM for a 40ft High Cube. Theoretical internal volumes are higher, but real stuffing loses space to pallet gaps and shape, so usable figures are used.

What is the maximum payload?

Typical maximum cargo payloads are around 28,000 kg for a 20ft and 26,500 kg for a 40ft or High Cube, after subtracting tare weight from the gross VGM limit. Always confirm the exact payload on your container's CSC plate.

What does volume-out versus weight-out mean?

Volume-out means you run out of space before hitting the weight limit, typical of light bulky cargo. Weight-out means you reach the weight limit with space to spare, typical of dense goods. The tool tells you which constraint binds first.

Why can't I fill 100 percent of the volume?

Cartons rarely tessellate perfectly and pallets, dunnage, and access aisles consume space. Practical utilisation of 80 to 90 percent of usable CBM is good. Using usable rather than theoretical volume already accounts for some of this.

Does this plan the exact stacking pattern?

No. It is a capacity check on total CBM and weight, not a 3D bin-packing optimiser. Use it to confirm a load fits and to balance volume against weight before you build a detailed stow plan.

What is the Container Stuffing & Utilisation Calculator?

Enter carton dimensions, weights, and quantities to total CBM and gross weight, then see percentage volume utilisation and payload utilisation against 20ft, 40ft, and 40ft High Cube container limits, flagging volume-out versus weight-out. It runs free in your browser on Gera Tools, with nothing uploaded.

Container Stuffing & Utilisation Calculator

Name: Container Stuffing & Utilisation Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Booking the right container and avoiding a weight-out or volume-out surprise at the port starts with a simple capacity check. This calculator totals the CBM and gross weight of your cartons and shows how much of a 20ft, 40ft, or 40ft High Cube container you would use.

What the calculator does — and what it doesn’t

This tool is a cargo capacity check, not a three-dimensional stow plan. It tells you whether your consolidated list of cartons fits inside a given container — by volume and by payload — and which constraint limits you first. It does not compute a specific stacking pattern or block-and-brace layout; that step comes after you’ve confirmed the load makes sense at the aggregate level.

Use this calculator to:

Confirm a full-container load (FCL) before booking a container type
Compare a 20ft versus a 40ft for a specific shipment
Identify whether you’re volume-limited or weight-limited
Spot overkill (booking a 40ft when 55% of a 20ft would do)

How CBM and gross weight are calculated

Each carton type contributes volume and weight. Totals are compared to usable container limits:

carton CBM   = (L × W × H in cm) ÷ 1,000,000
total CBM    = Σ (carton CBM × quantity)
total weight = Σ (carton gross weight in kg × quantity)
volume util  = total CBM ÷ usable container CBM
weight util  = total weight ÷ max payload

The usable volumes used are practical figures — about 33 CBM for a 20ft, 67 CBM for a 40ft, 76 CBM for a 40ft High Cube — which already reflect some packing loss compared to the raw internal theoretical volume. Whichever utilisation percentage hits 100% first is the binding constraint.

Container reference

Container	Usable CBM	Max cargo payload (approx)	Suited to
20ft GP	~33 CBM	~28,000 kg	Dense or heavy goods, smaller shipments
40ft GP	~67 CBM	~26,500 kg	General cargo, most mixed FCL loads
40ft HC	~76 CBM	~26,500 kg	Light bulky goods, palletised goods that stack high

Worked example

For illustration, take a mixed shipment with three carton types:

Type A: 100 cartons, 50 × 40 × 30 cm, 12 kg each → 0.060 CBM each → 6.0 CBM, 1,200 kg
Type B: 200 cartons, 60 × 45 × 40 cm, 20 kg each → 0.108 CBM each → 21.6 CBM, 4,000 kg
Type C: 50 cartons, 80 × 60 × 60 cm, 30 kg each → 0.288 CBM each → 14.4 CBM, 1,500 kg

Total: 42.0 CBM and 6,700 kg

Against a 40ft GP (67 CBM, ~26,500 kg payload): 63% volume utilisation, 25% weight utilisation. The load is clearly volume-limited and fits comfortably in a 40ft. You could theoretically consolidate more cargo on this booking or check whether a 20ft could be made to work with a tighter arrangement.

Practical targets

Aim for 80–90% volume utilisation. Perfect cube rarely happens because carton shapes don’t tessellate perfectly and some space is lost to dunnage, bracing, and access.
Never rely on theoretical internal volume. Actual stuffing always loses some space at the door end, corners, and under irregular carton combinations.
Verify payload on the CSC plate. The exact maximum payload varies between individual containers of the same type; always read the plate on your actual unit before confirming a weighty load.